ISSET
#define ISSET BIT(2) /* has value, vp->val.[si] */
#define ISSET(A, N) ((A)[(N)/BITS_PER_MAP] & (1<<((N)%BITS_PER_MAP)))
#define ISSET(opt) (sp->fts_options & (opt))
#define ISSET(v, n) ((v)[n])
#define ISSET(v, n) (((v) & ((unsigned long)1 << (n))) != 0)
#undef ISSET
#define ISSET(t, f) ((t) & (f))
#define ISSET(t, f) ((t) & (f))
#define ISSET(_w, _m) ((_w) & (_m))
#define ISSET FD_ISSET
#define ISSET(_v, _m) ((_v) & (_m))
} else if (ISSET(t->c_iflag, IXON|IXOFF)) {
} else if (ISSET(t->c_iflag, IXON|IXOFF)) {
#define ISSET(t, f) ((t) & (f))
#define ISSET(_i, _m) ((_i) & (_m))
#define ISSET(x, a) ((x) & (a))
#define ISSET(_a, _b) ((_a) & (_b))
#define ISSET(_v, _m) ((_v) & (_m))